jetting question yz426f 2002

anybody know the proper jetting for this model?



aftermarket exhaust (brand unknown)

need quick assistance


friend wants to know if there is a raceing setting for jetting too, i told him i think thats only with aftermarket exhaust.......

Stock is:

42 Pilot Jet

4th clip down on needle

162 Main Jet

Stock is:

42 Pilot Jet

4th clip down on needle

162 Main Jet

Yep, I can vouch for that.

cool, still need to check his to see what his is set at.....

do ya'lls head pipes glow red while at a stop, then cool off once moving

he said that when wide open it stops glowing, but out back when he first starts it up even at idle, his head pipe glows, ive lit my cigerette off it without even touching the darn thing...... any suggestions

Thats normal... Nothing to be alarmed about.

My jetting is:

pilot 42 (stock)

needle (stock)

main jet 160

fuel screw 1.75 turns out

i have a hmf performance slip on on my 02 and tried every clip position and jet size . it still rides like a 2-stroke

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